Metrology involves large numbers of parameters which are related to targets, target metrology conditions and production processes. Target design, production processes and metrology measurements exhibit varying degrees of sensitivity to these parameters which make it hard to evaluate parameter settings efficiently and make root cause analysis of metrology excursions difficult.
Metrology simulations are generally used to allow metrology engineers to predict the performance of metrology events and to evaluate the dependence of such performance on multiple input parameters. Examples of the input parameters that effect metrology performance include target geometric parameters, metrology system configuration and the film stack and feature topography on the wafer (and their tolerances) resultant from the semiconductor manufacturing process.